KeyForge

KeyForge lets users design their own authentication setup using passwords, signatures, and zk-based credentials. Each factor is committed on setup, and later the user generates a zero-knowledge proof showing they satisfied the chosen requirements. No secrets or signatures ever leave the device. Only a proof is sent on-chain. This give strong, flexible authentication with full privacy.

KeyForge is built using Noir, which handles all the proof construction and lets us combine different authentication factors inside a single circuit. The current factors are:

• a password check
• a secp256k1 signature verification
• a zkPassport proof, which we actually re-verify recursively inside our own circuit. The smart contracts are written in Solidity, and they handle on-chain verification of the aggregated proof. The whole system is designed so users can mix and match factors, and the circuit compiles a custom proof flow without needing to redeploy anything.